Low pressure-pulse kinetic pump

ABSTRACT

A centrifugal pump has a recessed impeller and a plurality of diffuser vanes fixed outwardly of the pumping chamber to convert fluid velocities to fluid pressures for output with minimum pressure pulse levels. Multiple axial rows of diffuser vanes may be used about the pumping chamber to further reduce pulse levels and noise in the pump output.

United States Patent [191 Korzec Nov. 11, 1975 LOW PRESSURE-PULSE KINETIC PUMP [75] Inventor: Walter Anthony Korzec, West Warren, Mass.

[73] Assignee: Warren Pumps, lnc., Warren, Mass.

[22] Filed: June 19, 1974 [21] Appl. No.1 480,977

[52] U.S. C1. 415/119; 415/207; 415/211; 415/213 A [51] Int. Cl. F04D 29/66; F04D 29/44 [58] Field of Search 415/211, 213 A, 207.119

[56] References Cited UNITED STATES PATENTS 2.042.550 6/1936 Puffer 415/211 2.114.285 4/1938 Berger 415/211 2.384.251 9/1945 Hill 415/211 3.103.177 9/1963 Gatto et a1 415/211 3.167.021 l/1965 Sence 415/213 A 3.759.628 9/1973 Kempf 415/213 A FOREIGN PATENTS OR APPLICATIONS 1.382.501 11/1964 France 413/213 A 10.984 1913 United Kingdom............ 415/211 419.544 11/1934 United Kingdom 415/211 Primury E.\aminerHenry F. Raduazo Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [5 7 ABSTRACT A centrifugal pump has a recessed impeller and a plurality of diffuser vanes fixed outwardly of the pumping chamber to convert fluid velocities to fluid pressures for output with minimum pressure pulse levels. Multiple axial rows of diffuser vanes may be used about the pumping chamber to further reduce pulse levels and noise in the pump output.

3 Claims, 7 Drawing Figures US. Patent Nov. 11,1975 SheetlofZ 3,918,829

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US. atent N0v.11, 1975 Sheet20f2 3,918,829

1 LOW PRESSURE-PULSE KINETIC PUMP BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to centrifugal pumps for incompressible fluids where small pressure pulses and low noise levels are desired.

2. Description of the Prior Art Centrifugal pumps in the prior art have directedfluid directly from the pumping chamber in which the spinning impeller is located to the outlet line. These pumps generally are both noisy and characterized by pressure pulses of substantial magnitude in the output. Reduction of the noise and smoothing out of the pulses by a secondary treatment of the pump output reduces pump efficiency.

SUMMARYUOF THE INVENTION In this invention the disc impeller is recessed in the casing adjacent the pumping chamber so as to be outside the main path of fluid flow from the fluid inlet to the pump outlet. A set of diffuser vanes having leading edges tangential to the pumping chamber and axially adjacent the edge of the impeller disc guides the flow tangentially and radially, or spirally outward, to an outlet chamber of appreciable cross section. Fluid in the pumping chamber is swirled as in a vortex by action of the spinning impeller, with fluid actually engaged by the vanes on the impeller entraining additional fluid through a vortex action. Long diffuser vances convert the high velocity or kinetic energy of the fluid into pressure energy in the outlet channel surrounding the diffuser vanes. Flow in the outlet channel is directed through a tangential outlet opening from the pump.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a cross sectional view from the front of the pump of FIG. 1, along section IIII;

FIG. 3 is a cross sectional view from the side of a second configuration of the pump;

FIG. 4 is a cross sectional view from the front of the pump of FIG. 3;

FIG. 5 shows a cross-sectional view from the side of a pump combining features shown in FIGS. 1 and 3;

FIG. 6 is a cross sectional view of one embodiment of a rotary impeller which may be used in any of the pump configurations; and

FIG. 7 shows in cross-section a second embodiment of the rotary impeller of the pump.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of a pump 10 having the features of the present invention. The pump 10 is comprised of casing parts 11 and 12. The rear of the casing 11 has a shaft bore 13 in which is rotably mounted a shaft 14 which carries within the casing a rotable impeller 15. The impeller 15 rotates within a recess 16 in one side of the casing 11 adjacent the pumping chamber 17. Fluid enters the pumping chamber 17 from an inlet 18 formed in the intake port casing of part 12 where some of it is engaged by the vanes 19 of the spinning impeller 15 to form vortices 20 within the pumping chamber. Fluid escapes from the pumping chamber 17 through diffuser vanes 21 and 22 which are circumjacent the pumping chamber and guide the fluid spirally outward from the pumping chamber to an outlet chamber 23. The outlet 23 is of appreciable cross section so that fluid therein may 'move slowly and have a pressure appreciably increased over that in the pumping chamber 17. Pressurized fluid in the outlet chamber 23 escapes tangentially therefrom through a fluid outlet 24. A radial disc 25 fixed between the two sets of diffuservanes 21 and 22 serves to separate the flow between the two sets of vanes and thereby to secure smaller pressure pulses in the flow of fluid from the pumping chamber l7t'o the outlet chamber 23.

FIG. 3 shows an altern ative embodiment of the pump of the present invention. In this embodiment the pump casing is provided in substantially one piece'31, having a rear plate "32 closing the rear thereof behind the impeller l5 and carrying the shaft bore- 13. By this construction the impeller 15 may be removed from the pump casing 31 from the rear of the pump without disturbing the inlet and outlet piping. A further characteristic of the pump 30 shown in FIG. 3 is provision of a single set of diffuser vanes 33 about the periphery of the pumping chamber 17. The vanes 33 convert the kinetic energy of the fluid motion developed within the chamber 17 into pressure energy in the outlet passages 23 as before, with somewhat simpler construction but producing somewhat greater pressure pulses than the configuration of FIG.. 1 for the same number of vanes.

FIG. 5 shows the diffuser vane configuration of FIG. 3 within the two part casing of FIG. 1, which requires that the impeller 15 be inserted into the pump and withdrawn from the pump only upon disconnection fo either the inlet or outlet plumbing. It should be understood that although the diffuser vanes 33 shown in FIGS. 3 and 5 and 21 and 22 in FIG. 1 are shown as constructed integrally with the case parts 41, 31, and 12, respectively, they may just as well be constructed separately and keyed into the pump housing during construction.

The impeller 15 may be constructed with a flat plate 51 with open edges as shown in FIGS. 15, and 6, having a hub portion 52 to which the shaft 14 is attached and vanes 19 extending spirally outwardly between the hub and edges of the plate to sweep fluid outwardly as the impeller 15 rotates. The vanes 19 may be confined laterally within the recess 16 of the pump casing as shown in FIGS. 1, 3, and 5, or they may extend into the pumping chamber 17 if greater pressures must be developed by the pump. The impeller .15 shown in FIGS. 1-5 in cross-sectional and front views is shown in FIG. 6 in side view. FIG. 7 shows an alternative embodiment of the impeller, 15', which has a closed impeller plate 55 with upwardly sloping edges around the periphery thereof to direct fluid out from the impeller to the vortices of the pumping chamber 17. Reinforcing segments 56 are provided along the underside of the impeller 15.

It should be understood that the number of diffuser vanes 21, 22 or 33 and the number of impeller vanes 19 must be fixed with the requirements of the particular application to which the pump is to be put in mind and that the particular numbers of vanes shown are merely representative here. Further, the invention may readily be employed in centrifugal pumps of other configurations than are shown here, including double suction, side inlet/outlet, multi-stage, and other types without deviation from the concepts herein disclosed.

Although various modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. A centrifugal pump comprising:

an intake port casing having at least two circumferential rows of diffuser vanes spaced radially outwardly from an axis of said casing,

the vanes having inner leading edges forming a free vortex chamber radially inwardly thereof and axially adjacent said intake port casing,

the rows of vanes being separated each from another by an annular, radially-extending surface,

the vanes on either axial side of said surface being staggered circumferentially with respect to one another, and

the rows of diffuser vanes being formed integrally with said intake port casing; and

a rotatable impeller recessed axially in an impeller chamber formed in a second casing part adjoining said free vortex chamber,

thereby to reduce pump noise and pump output pressure pulse magnitude.

2. A centrifugal pump as defined in claim 1 and further comprising:

said impeller is rotatable on said axis of said casing, and further comprises:

a circular plate bounding said impeller chamber and having an edge spaced radially inwardly from the inner leading edges of said diffuser vanes; and

impeller vanes on a side of said plate adjacent the free vortex chamber and extending substantially from said axis spirally outwardly to said edge. 

1. A centrifugal pump comprising: an intake port casing having at least two circUmferential rows of diffuser vanes spaced radially outwardly from an axis of said casing, the vanes having inner leading edges forming a free vortex chamber radially inwardly thereof and axially adjacent said intake port casing, the rows of vanes being separated each from another by an annular, radially-extending surface, the vanes on either axial side of said surface being staggered circumferentially with respect to one another, and the rows of diffuser vanes being formed integrally with said intake port casing; and a rotatable impeller recessed axially in an impeller chamber formed in a second casing part adjoining said free vortex chamber, thereby to reduce pump noise and pump output pressure pulse magnitude.
 2. A centrifugal pump as defined in claim 1 and further comprising: means forming an outlet chamber surrounding said diffuser vances circumferentially; and an outlet port arranged tangentially from said outlet chamber, thereby to collect and distribute fluid acted upon by said pump.
 3. A centrifugal pump as defined in claim 1, wherein said impeller is rotatable on said axis of said casing, and further comprises: a circular plate bounding said impeller chamber and having an edge spaced radially inwardly from the inner leading edges of said diffuser vanes; and impeller vanes on a side of said plate adjacent the free vortex chamber and extending substantially from said axis spirally outwardly to said edge. 